“The sheet of ice is acting like dam,” says Plumb, a hydrologist with the National Weather Service in Fairbanks. “And it’s causing the Yukon River to flood over its banks and flood a large portion of the area upriver from the ice jam so reports are that the water has spread out over several miles on either side of the Yukon river out into the forest and into the flats.”

Plumb says high water along the river has already caused minor flooding in Fort Yukon. He says likely, flooding will get worse after the ice jam breaks.

“One other concern that we have too is that downriver from Fort Yukon, the ice is still in place and hasn’t moved out yet,” he explains. “And so after this jam releases, and ice and water start moving down river again, it could jam below Fort Yukon and if that happens, Fort Yukon could see major flooding if water starts to back up behind an ice jam that may form downriver.”